A moderation layer to improve the safety behavior of sodium cooled fast reactors


A moderation layer to improve the safety behavior of sodium cooled fast reactors

Merk, B.; Weiß, F.-P.

The nature of the sodium void effect in an infinite lattice is discussed with all different contributions. In a next step, the insertion of a layer consisting of moderating material for a reduction of the effect is proposed. The effect of three different moderating layers on the sodium void defect, the neutron spectrum, and the kinf over burnup is investigated. Special emphasis is given to the influence of the moderation layer on the feedback effects. Especially the uranium-zirconium hydride UzrH layer causes a strong reduction of the sodium void effect. Additionally this layer improves the fuel temperature effect and the coolant effect of the system significantly. All changes cause by the insertion of the UZrH layer lead to a significant increase in stability of the fast reactor system against transients. The moderating layers have only a small influence on the breeding effect and on the production of minor actinides. The insertion of the moderating layer does not imply any constraints on the core design and the power distribution in the fuel element an. Thus the use of a moderation layer gives the opportunity of designable feedback effects in a fast reactor core.

Keywords: Sodium Void Effect; SFR; Fast Reactor; Uranium-Zirconium Hydride; Boron Carbide

  • Contribution to proceedings
    International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering (M&C 2011), 08.-12.05.2011, Rio de Janeiro, Brazil, ISBN 978-85-63688-00-2
  • Lecture (Conference)
    International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering (M&C 2011), 08.-12.05.2011, Rio de Janeiro, Brazil

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Publ.-Id: 14835